login via ldap prevented by old user in database

[Duni]

Hello,

Some users cannot authenticate to jellyfin using LDAP Authentication.
From the logs, it seems the bind is done using the wrong username: 

Code:

[2025-12-21 23:25:24.881 +01:00] [WRN] User Manager could not find an user with such ldapUid, this may not be fatal
System.NullReferenceException: Object reference not set to an instance of an object.
  at Jellyfin.Plugin.LDAP_Auth.LdapAuthenticationProviderPlugin.Authenticate(String username, String password)
[2025-12-21 23:25:24.881 +01:00] [WRN] User Manager could not find an user with such ldapUsername, this may not be fatal
System.NullReferenceException: Object reference not set to an instance of an object.
  at Jellyfin.Plugin.LDAP_Auth.LdapAuthenticationProviderPlugin.Authenticate(String username, String password)
[2025-12-21 23:25:24.914 +01:00] [ERR] User not configured for LDAP Uid: "Solène"
[2025-12-21 23:25:24.914 +01:00] [INF] Authentication request for "Solene" has been denied (IP: "127.0.0.1").
[2025-12-21 23:25:24.915 +01:00] [ERR] Error processing request: "Invalid username or password entered". URL "POST" "/Users/authenticatebyname".

Here the user from the jellyfin dashboard & ldap database is named "solene", while ldapauth tries to bind using "Solène" as the username.

I had multiple users containing special characters in their names like this one, which I deleted when configuring LDAP. 
I then created new users without the special chars in the name (so I deleted the user Solène, created a new user solene).

But it seems the old user still exists somewhere in the database, and ldapAuth is wrongly using it to authenticate.
I ran the  optimize database and cleanup user data tasks but it did not fix the issue.

So I wonder if there is an easy way to just delete the old unused user from the jellyfin database or make the ladapauth plugin use the right user?

If I try to query the user from the ldap auth settings it is found in the ldap database.